The experimental study of the determination of knocking limits in a spark ignition engine using ethanol as an alternative fuel

Exhaust emissions cause of from internal combustion engine is getting more dangerous for environment with each passing day. Carbon dioxide, one of the gases every day released from exhaust of millions of vehicles to the environment, is the main reason of global warming. However, in recent time running out of fossil based fuels used in the present, guides researchers to search renewable energy.In this study, the effects of using unleaded gasoline (E0) and blend of unleaded gasoline-ethanol (E85) on knock were investigated experimentally. Also engine performance values such as engine torque and specific fuel consumption and exhaust emissions were researched.Experiments were performed in four-stroke, single cylinder, variable compression ratio, fuel injection with a spark ignition Hydra brand engine; at two different engine speeds as 1500 rpm and 2000 rpm, and at two different compression ratio in for 10/1 and 11/1, by changing ignition timing and excess air coefficient.The result of experimental study it is determined that knock strength of E85 fuel is higher relatively E0 fuel. When E85 fuel supply a higher engine torque relatively E0 fuel at 10/1 compression ratio; E85 fuel supply very near engine torque value of E0 fuel at 11/1 compression ratio. Brake specific fuel consumption is a bit higher because of being low calorific value of ethanol; its seen that exhaust emissions are lower. All these results show that E85 fuel will be able to be used at spark ignition engines as an alternative fuel.